Interaction of proteoglycans with the pericellular (1 alpha, 2 alpha, 3 alpha) collagens of cartilage

Interaction between cartilage proteoglycan and the collagen(s) composed of 1 alpha, 2 alpha, and 3 alpha chains was studied in vitro. Most of the collagen was insoluble under the conditions of assay (0.15 M NaCl, 0.008 M phosphate buffer, pH 7.4; 4 degrees C) and was in the form of fibrils 20 nm in diameter or thinner. The larger fibrils had 60-70 nm periodicity, characteristic of native collagens. Proteoglycan monomers which had been labeled by incubating cartilage slices in vitro with Na2 35SO4 were used to assay the interaction. The insoluble collagen fraction bound proteoglycan from solution. At proteoglycan:collagen ratios lower than 1:2, binding was rapid and linear, and the dissociation constant was 1.7 X 10(-9) M. At higher proteoglycan:collagen ratios, more proteoglycan was bound, but at a slower rate. Binding of proteoglycan to collagen did not require fibrils, since soluble 1 alpha, 2 alpha, and 3 alpha containing collagen also bound to proteoglycan and formed an insoluble complex. Denatured collagens did not bind proteoglycan or compete for binding with normal collagen. Optimum binding occurred with intact proteoglycan, but proteoglycan which had been treated with protease was also bound at low levels. Both protease-treated proteoglycan and free chondroitin sulfate competed with intact proteoglycan in the binding assays, but neither chondroitinase ABC-treated proteoglycan nor the oligosaccharides produced by digestion of chondroitin sulfate with testicular hyaluronidase altered the binding of proteoglycan to collagen. Hyaluronic acid did not compete with radioactive proteoglycan, but heparin and dextran sulfate were extremely effective inhibitors of binding. These data suggest a relatively nonspecific interaction between sulfated polyanions and 1 alpha, 2 alpha, and 3 alpha containing collagens. However, given the location of these collagens near the chondrocyte surface, the interaction of fibrillar 1 alpha, 2 alpha, 3 alpha collagen with proteoglycan is likely to occur and to be of biological importance.

Phenotype, activation status, and suppressor activity of host lymphocytes during acute rejection and after cyclosporine-induced unresponsiveness of rat cardiac allografts

Serial changes in phenotype, cell cycle, and functional behavior of lymphocyte subpopulations occurring both during acute rejection in unmodified hosts and in long-surviving heterotopic cardiac allografts in rats treated with cyclosporine (CsA) were studied. Using flow cytometry, RNA and DNA content of cells was examined during various phases of cell activation. In animals acutely rejecting their grafts, numbers of cells infiltrating the grafts and in host spleen in G1 phase (higher RNA content) increased, starting from day 3, and peaked by 5-6 days posttransplantation, and numbers of cells in S/G2/M phase (higher DNA content) remained stable. Similar, although slightly delayed changes were noted in CsA-treated recipients. The ratio of T helper (Th) to T suppressor/cytotoxic (Ts/c) phenotype cells infiltrating acutely rejecting grafts by day 3, was 1.6; it inverted abruptly to 0.7 by days 5-6, suggesting a preponderance of Ts/c during the later stages of allograft rejection. Ratio inversion occurred slightly later in host spleen and later in peripheral blood. Similarly, treatment with CsA produced a transient depression of Th, with recovery of the Th: Ts/c ratio during weeks 3-4 following transplantation. Adoptive transfer studies were then performed to investigate the functional significance of the T cell subsets. Survival of test grafts was prolonged significantly (ca. 14 days, P less than 0.001) when cells infiltrating grafts and spleen were transferred during inversion of Th:Ts/c; before that period, test graft survival was shortened in a second-set manner. These experiments suggest that suppressor cells may be responsible for resolution of acute rejection, as well as for host unresponsiveness seen after CsA treatment, and they represent an important homeostatic host mechanism following immunological stimulation.

Interleukin-2 apparently upregulates its receptor and induces proliferation of various resting mononuclear leukocytes in the absence of antigen

We demonstrate that exposure to highly purified recombinant interleukin 2 (rIL-2) in the absence of known antigenic stimulation induces/increases the expression of two activation-associated proteins, the interleukin 2 receptor (IL-2R) and 4F2 on "resting" peripheral blood mononuclear cells (PBMC); subsequently, these cells enter the S phase of the cell cycle and proliferate. Dual parameter flow cytometry indicates that the phenotype of the cell population(s) which proliferate following this treatment includes HNK+, DR+, and T3+ cells. A twofold expansion in the number of HNK+ and DR+ cells was observed upon culturing resting PBMC in rIL-2 over a 6-day culture period. While the HNK monoclonal antibody is not specific for NK cells, these data do suggest that antigen independent growth of HNK+ cells may represent an additional mechanism by which IL-2 enhances NK effector activity, i.e., by induction of clonal growth of NK cells. In contrast, several concentrations of recombinant Interferon-gamma failed to produce a similar proliferative response.

Purification, characterization and immunological properties of the capsular polysaccharide of Pasteurella haemolytica serotype T15: its identity with the K62 (K2ab) capsular polysaccharide of Escherichia coli and the capsular polysaccharide of Neisseria meningitidis serogroup H

Capsular polysaccharide from two strains of Pasteurella haemolytica serotype T15 was purified and characterized by chemical analysis and NMR spectroscopy. The polymer, a teichoic acid, proved to be very similar in structure to the capsular polysaccharide of P. haemolytica serotype T4 and identical to the previously described K62 (K2ab) capsular polysaccharide of Escherichia coli, and the capsular polysaccharide of Neisseria meningitidis serotype H, i.e. ----(2-glycerol-3)----(phosphate)----(4-alpha-D-galactopyranose -1)---- with partial O-acetylation on the galactose residues. Electron microscopy with Protein A-gold labelled antisera showed that the polysaccharide was peripherally located on the surface of all three organisms. Chemical removal of O-acetyl groups from the polysaccharide yielded a structure identical to that previously described for E. coli K2 (K2a). Both O-acetylated and de-O-acetylated P. haemolytica T15 polymers, when absorbed on to sheep erythrocytes in passive haemagglutination assays, yielded identical antibody titres with sera raised against P. haemolytica T15, E. coli K2 or N. meningitidis H whole cells. De-O-acetylation of the Pasteurella polysaccharide influenced its precipitability with immune sera, but this could not be related to the absence of O-acetyl groups because the non-acetylated E. coli K2 polymer readily precipitated with a line of 'identity' with the acetylated P. haemolytica T15 polymer.

The early (18-hr) human mixed lymphocyte reaction: identification and isolation of activated T-cell clones

This study provides direct evidence that de novo expression of the activation antigens B1 49.9 (49.9) (interleukin-2 receptor) and 4F2 enables identification of alloactivated cells within 18 hr of initiation of human mixed lymphocyte reactions (MLR). Using a dual-parameter flow cytometer (simultaneous assessment of immunofluorescence and DNA content on the same cell), it was demonstrated that these activation antigens emerge before activated cells enter into S/G2/M phase of the cell cycle. Family studies illustrate that early activation antigen appearance occurs in response to a mismatch at chromosome 6, and invariably heralds the proliferative outcome at 6 days of MLR. In order to directly study the small alloactivated T-cell population, 49.9-positive cells were isolated using a cell sorter after 18 hr of MLR and cloned by limiting dilution using purified recombinant interleukin-2 (rIL-2). Antigen-specific T4-positive T-cell clones were isolated. Analysis of these clones demonstrates that antigen-specific reactivity is acquired within 18 hr in the MLR. These methods should permit a dissection of the early events of alloactivation.

Anxiety in the child dental clinic

A study was made of differences between children who had a history of refusing dental treatment in the community and control children, as rated by their parents. History of treatment refusal was found to be associated with a general fear of 'medical' people, intolerance for any pain or discomfort and greater difficulty in approaching novelty or adapting to change. These children were also rated by their parents as being generally more negative in their mood and having greater difficulty in playing with unfamiliar children. The implications of these findings are discussed.

The effect of high and low assertiveness on locus of control and health problems

The effect of high and low assertiveness on locus of control and health problems was examined with 78 direct-service workers in mental health and mental retardation settings in northeastern Pennsylvania. The direct-service workers completed the Rathus (1973) Assertiveness Schedule, the Rotter (1966) Internal-External Locus of Control Scale, and a health-problems inventory. Highly assertive individuals were found to be more internally controlled and to experience fewer health problems than were individuals low in assertiveness.

Benoxaprofen reduces osteophyte formation and fibrillation after articular cartilage injury

We examined the in vivo effect of benoxaprofen on the degeneration of articular cartilage after injection of sodium iodoacetate into the guinea pig knee. As shown previously, 3 weeks after the injection, samples from the ipsilateral knee of animals that did not receive benoxaprofen invariably exhibited marked loss of chondrocytes, absence of staining with safranin-O, fibrillation, and prominent osteophytes. In contrast, in samples from animals which received daily benoxaprofen (25 mg/kg) orally after the intraarticular injection of iodoacetate, pericellular safranin-O staining persisted, cell loss was less marked, osteophyte formation was markedly diminished and fibrillation occurred in only one of 5 samples. Knee cartilage from 2 animals that received benoxaprofen but were not injected with iodoacetate exhibited focal fibrillation, which may have been unrelated to the drug. Thus, benoxaprofen exhibited a marked protective effect in this chemically induced model of cartilage injury.

Purification, characterization and immunological properties of the serotype-specific capsular polysaccharide of Pasteurella haemolytica (serotype T4) organisms

The serotype-specific capsular polysaccharide from two strains of Pasteurella haemolytica serotype T4 organisms was purified and characterized by chemical analysis and NMR spectroscopy. The polymer, a teichoic acid, has the backbone structure ----(2-glycerol-l)----(phosphate)----(6-alpha-D-galactose-1)---- and is partially O-acetylated on the C2 and C3 galactose residues. Chemical removal of O-acetyl groups from the polysaccharide destroyed both its ability to precipitate with antiserum raised against killed whole serotype T4 organisms and its ability to adhere to sheep erythrocytes in passive haemagglutination experiments. Attempts to elicit antisera using the purified polymer were unsuccessful but a partially purified material was immunogenic.

T cell synergy in the primary MLR: proliferative kinetics, effector cell generation, and IL 2 production

A primary rat MLR was initiated, and on each of 8 consecutive days during the evolving culture, an aliquot of cells was separated into its constitutive helper/inducer (W3/25+) and suppressor/cytotoxic (OX8+) T cell subsets by a monoclonal antibody, Degalan-bead immunoadsorbent column technique. This allowed a detailed kinetic analysis of T cell proliferation, the generation of effector cells, and the production of IL 2 by each subset relative to net whole culture supernatant IL 2 activity. The primary MLR demonstrates an early period of helper/inducer cell proliferation, IL 2 production and accumulation, followed by a period of suppressor/cytotoxic cell (OX8+) proliferation and IL 2 consumption during which there are distinct waves of allospecific suppressor, followed by cytotoxic activity. If fresh T cells of the helper/inducer or suppressor/cytotoxic phenotype were preseparated and then cultured alone with irradiated allogeneic stimulator cells, proliferation was noted in both subsets despite no demonstrable IL 2 activity in cultures of the suppressor/cytotoxic cells. Finally, a suppressed primary MLR exhibited proliferative inhibition of both T cell subsets.

Exercise increases osteophyte formation and diminishes fibrillation following chemically induced articular cartilage injury

The present study shows that a treadmill exercise regimen imposed on guinea-pigs whose articular cartilage has been damaged by intra-articular injection of IA reduces chondrocyte depletion, results in an increase in pericellular Safranin-O staining around surviving chondrocytes, and prevents fibrillation of the articular surface. The data suggest that exercise protected, or facilitated recovery of, chondrocytes subjected to chemical injury, and that the surviving cells then synthesised a matrix which was sufficiently normal to withstand impulsive joint loading. On the other hand, the exercise regimen accelerated osteophyte formation, and led to formation of osteophytes in sites at which they did not develop in animals which received intra-articular IA but which were not exercised.

T cell synergy in the primary MLR: proliferative kinetics, effector cell generation, and IL 2 production

A primary rat MLR was initiated, and on each of 8 consecutive days during the evolving culture, an aliquot of cells was separated into its constitutive helper/inducer (W3/25+) and suppressor/cytotoxic (OX8+) T cell subsets by a monoclonal antibody, Degalan-bead immunoadsorbent column technique. This allowed a detailed kinetic analysis of T cell proliferation, the generation of effector cells, and the production of IL 2 by each subset relative to net whole culture supernatant IL 2 activity. The primary MLR demonstrates an early period of helper/inducer cell proliferation, IL 2 production and accumulation, followed by a period of suppressor/cytotoxic cell (OX8+) proliferation and IL 2 consumption during which there are distinct waves of allospecific suppressor, followed by cytotoxic activity. If fresh T cells of the helper/inducer or suppressor/cytotoxic phenotype were preseparated and then cultured alone with irradiated allogeneic stimulator cells, proliferation was noted in both subsets despite no demonstrable IL 2 activity in cultures of the suppressor/cytotoxic cells. Finally, a suppressed primary MLR exhibited proliferative inhibition of both T cell subsets.

Accessory cell requirement for activation antigen expression and cell cycle progression by human T lymphocytes

Stringent accessory cell (AC) depletion by a three-step procedure--plastic adherence, nylon wool adherence, followed by simultaneous treatment with two anti-AC monoclonal antibodies + complement--has allowed the demonstration of several AC-dependent stages in the T cell activation pathway. Simultaneous analysis of DNA content and cell surface immunofluorescence (correlation of activation antigen expression with cell cycle position) or DNA and RNA content (cell cycle position) of cultured cells was accomplished by dual parameter flow cytometry. AC-depleted, PHA-stimulated human peripheral blood T lymphocytes (PBTL) failed to exhibit "early" indicators of activation, including increased RNA content, expression of three activation-associated cell surface proteins (IL 2 receptor, transferrin receptor, and 4F2 protein), and the production of IL 2. The AC-depleted PBTL that failed to express these "early" markers of activation also failed to progress into the "late" phase of activation, DNA synthesis. All indicators of PHA responsiveness were fully replenished upon addition of AC but were only reconstituted to intermediate levels by addition of excess quantities of either highly purified IL 1 or crude AC-conditioned medium with lymphocyte-activating factor activity. These data suggest that the AC membrane plays a key and as yet undefined role in the stimulation of T cells by PHA.

Accessory cell requirement for activation antigen expression and cell cycle progression by human T lymphocytes

Stringent accessory cell (AC) depletion by a three-step procedure--plastic adherence, nylon wool adherence, followed by simultaneous treatment with two anti-AC monoclonal antibodies + complement--has allowed the demonstration of several AC-dependent stages in the T cell activation pathway. Simultaneous analysis of DNA content and cell surface immunofluorescence (correlation of activation antigen expression with cell cycle position) or DNA and RNA content (cell cycle position) of cultured cells was accomplished by dual parameter flow cytometry. AC-depleted, PHA-stimulated human peripheral blood T lymphocytes (PBTL) failed to exhibit "early" indicators of activation, including increased RNA content, expression of three activation-associated cell surface proteins (IL 2 receptor, transferrin receptor, and 4F2 protein), and the production of IL 2. The AC-depleted PBTL that failed to express these "early" markers of activation also failed to progress into the "late" phase of activation, DNA synthesis. All indicators of PHA responsiveness were fully replenished upon addition of AC but were only reconstituted to intermediate levels by addition of excess quantities of either highly purified IL 1 or crude AC-conditioned medium with lymphocyte-activating factor activity. These data suggest that the AC membrane plays a key and as yet undefined role in the stimulation of T cells by PHA.

A method for the selective release and, hence, assay of the carbohydrate moieties of collagen

The carbohydrate residues of collagen were selectively released in high yield by nitrosation of the hydroxylysines of the intact collagen or peptides derived from collagen. The carbohydrate residues (Glc-Gal and Gal) released were separated from the modified protein or peptide by gel chromatography and were assayed by gas-liquid chromatography of their trimethylsilyl derivatives. The results agreed closely with those obtained from methanolysis-gas chromatography or from alkaline hydrolysis followed by amino acid analysis of the hydroxylysyl glycosides. With a more sensitive perbenzoylation-high-performance liquid chromatography method and uv detection at 230 nm, the carbohydrates released by nitrosation of submilligram quantities of collagen or peptide could be assayed accurately.

Cognitive-behaviour therapy for depression: problems and perspectives

A number of reviews of the effectiveness of cognitive behaviour therapy for depression, though optimistic, have pointed to some difficulties in interpretation of the outcome literature. These difficulties, and the extent to which more recent research has dealt with them, are reviewed. It is suggested that while some of the genuine difficulties have been resolved, and other commonly expressed criticisms may prove to be unfounded, there remain a number of important areas of ignorance which demand further investigation.

Predicting outcome from closed head injury by early assessment of trauma severity

The relationship between severity of head injury and outcome was studied in 96 patients. Severity was assessed based on the level of coma and presence of mass lesion, hemiparesis, skull fracture, and pupil abnormality. Outcome was assessed using the Wechsler Adult Intelligence Scale, the Halstead-Reitan neuropsychological battery, and the Glasgow Outcome Scale. The relationship between assessment of severity of trauma and the outcome measurements was calculated by multiple regression analysis. Results indicate that coma grade and estimates of premorbid intelligence quotient (IQ) served best to predict IQ as assessed after the injury. The combination of coma grade, mass lesion, and skull fracture were important predictors of the Halstead Impairment Index. Coma grade and pupil abnormality predicted the Glasgow Outcome Scale. Low to moderate relationships were found between the predictor variables and the measurement of IQ and the Glasgow Outcome Scale; multiple regression coefficients were 0.63 and 0.61, respectively. The relationship between measurement of trauma severity and the Halstead Impairment Index was also low (R = 0.37).

Surgical correction of type I dissecting aortic aneurysm after renal transplantation

While Type III dissecting aneurysms of the aorta in patients with renal transplants have been described, this report appears to represent the first successful replacement of the ascending aorta with correction of valvar aortic insufficiency in a patient with a Type I aortic dissection. The operative result and subsequent clinical course have been gratifying. On the basis of these findings an aggressive surgical approach is recommended for patients with this combination of conditions.

Temporary immobilisation facilitates repair of chemically induced articular cartilage injury

Recent studies have indicated that immobilisation of the lower limb may prevent surface fibrillation and osteophyte formation, and reduce cell depletion, following injection of iodoacetate into the ipsilateral knee of the guinea-pig. The present study shows that temporary immobilisation also facilitates repair of the damaged cartilage during a subsequent period of remobilisation in which the animal is permitted to move 'on all fours'. Thus, in animals killed six weeks after a single intra-articular injection of iodoacetate (0.3 mg in 0.1 ml saline), and in which the injected knee had been immobilised for three weeks, Safranin-O staining of the articular cartilage was more intense, chondrocyte density greater, and osteophytosis much less marked than in animals injected with iodoacetate but killed immediately after the three weeks immobilisation period. By contrast, immobilisation for only one week failed to protect against degenerative changes and osteophytes caused by iodoacetate injection. Immobilisation alone produced no apparent pathological changes in animals which did not receive iodoacetate.

Dual parameter flow cytometric analysis of DNA content, activation antigen expression, and T cell subset proliferation in the human mixed lymphocyte reaction

This study provides direct correlation via dual parameter flow cytometry (simultaneous assessment of immunofluorescence and DNA content) between mixed lymphocyte reaction (MLR) responder cell entry into the S/G2/M phases of the cell cycle with the kinetics of expression of two activation-associated cell surface proteins, Tac (IL 2 receptor) and 4F2 (unknown metabolic function). A small population of activated cells was identifiable by expression of both Tac and 4F2 antigens before peak DNA synthesis in the MLR. This population of activation antigen-positive cells expanded linearly in size from days 3 to 7 of culture. Treatment of immature MLR cultures with anti-4F2 Mab and complement (C) before DNA synthesis (treatment on day 3, peak DNA synthesis on days 5 to 6) resulted in blunted proliferation and activation antigen expression when the same culture was analyzed after maturation on day 6, indicating that the activated population had been previously detected and removed by anti-4F2 Mab + C. The 4F2 antigen was expressed on a greater percentage of cells in the MLR at all times (days 3 to 9) than was Tac, was present on virtually all S/G2/M phase responder cells, and a large fraction of cells remained intensely 4F2+ subsequent to peak DNA synthesis. In contrast, after initially preceding responder cell entry into the S phase of the cell cycle, the kinetics of Tac antigen expression closely paralleled the kinetics of responder cell proliferation. A subpopulation of cycling responder cells was noted in all MLR cultures studied that expressed Tac antigen weakly or not at all. Cells within both T4 and T8 cell subsets proliferate with similar kinetics in response to alloantigen. The possibility that activation antigens can be utilized to study effector cell generation in the MLR and that this flow cytometric technique may be utilized to analyze the response to various alloantigens is discussed.

Dual parameter flow cytometric analysis of DNA content, activation antigen expression, and T cell subset proliferation in the human mixed lymphocyte reaction

This study provides direct correlation via dual parameter flow cytometry (simultaneous assessment of immunofluorescence and DNA content) between mixed lymphocyte reaction (MLR) responder cell entry into the S/G2/M phases of the cell cycle with the kinetics of expression of two activation-associated cell surface proteins, Tac (IL 2 receptor) and 4F2 (unknown metabolic function). A small population of activated cells was identifiable by expression of both Tac and 4F2 antigens before peak DNA synthesis in the MLR. This population of activation antigen-positive cells expanded linearly in size from days 3 to 7 of culture. Treatment of immature MLR cultures with anti-4F2 Mab and complement (C) before DNA synthesis (treatment on day 3, peak DNA synthesis on days 5 to 6) resulted in blunted proliferation and activation antigen expression when the same culture was analyzed after maturation on day 6, indicating that the activated population had been previously detected and removed by anti-4F2 Mab + C. The 4F2 antigen was expressed on a greater percentage of cells in the MLR at all times (days 3 to 9) than was Tac, was present on virtually all S/G2/M phase responder cells, and a large fraction of cells remained intensely 4F2+ subsequent to peak DNA synthesis. In contrast, after initially preceding responder cell entry into the S phase of the cell cycle, the kinetics of Tac antigen expression closely paralleled the kinetics of responder cell proliferation. A subpopulation of cycling responder cells was noted in all MLR cultures studied that expressed Tac antigen weakly or not at all. Cells within both T4 and T8 cell subsets proliferate with similar kinetics in response to alloantigen. The possibility that activation antigens can be utilized to study effector cell generation in the MLR and that this flow cytometric technique may be utilized to analyze the response to various alloantigens is discussed.

Immobilization ameliorates chemically-induced articular cartilage damage

We have previously shown that immobilization protects against the development of mechanically-induced osteoarthritis following-anterior cruciate ligament transection in dogs. Herein, we examine the effect of immobilization of the leg on the chemically-induced degeneration of femoral articular cartilage caused by intraarticular injection of iodoacetate in guinea pigs. One week after the injection, cartilage from animals which were not immobilized exhibited a decrease in Safranin O staining and a 10-20% reduction in the number of chondrocytes. Three weeks after injection, cell death and loss of Safranin O staining had progressed, and surface fibrillation and osteophytes had developed. Articular cartilage from the contralateral (uninjected) knees of guinea pigs which received iodoacetate, and from knees of animals which were immobilized for 1 week but did not receive iodoacetate, was histologically and histochemically normal. However, specimens from 2 of 4 untreated knees which were immobilized for 3 weeks showed a reduction in Safranin O staining. Immobilization of the knee did not alter the loss of Safranin O staining seen after intraarticular iodoacetate injection, but did reduce the depletion of chondrocytes (P less than 0.05). Furthermore, neither osteophytes nor fibrillation developed in any of the animals which were constrained after iodoacetate injection. Thus, immobilization was clearly protective in this model of chemically-induced cartilage injury.

Recovery from severe closed head injuries: repeat testings with the Halstead-Reitan Neuropsychological Battery

Evaluated 15 adult patients who were suffering severe, coma-producing closed head injuries for neuropsychological and intellectual impairment with the Halstead-Reitan Neuropsychological Battery and the Wechsler Adult Intelligence Scale. All Ss were tested shortly after the time of their accidents and were reevaluated at approximately 1 year posttrauma to document residual deficits and rate of recovery. A group of 15 neurologically normal control Ss, matched for age, education, and sex, received the same battery of psychological tests. Although the brain-injured group demonstrated improvement on essentially all of the dependent measures from first testing to second, comparisons made with the control group revealed numerous areas of residual impairment, which suggests only partial recovery during the first year posttrauma.

Immunofluorescence measurement in a flow cytometer using low-power helium-neon laser excitation

Helium-neon lasers are economical and efficient light sources; their utility in flow cytometry to date has been limited by the lack of fluorescent probes that can be excited at 633 nm. Allophycocyanin (APC), a highly fluorescent phycobiliprotein, can be used as an antibody label and has spectral characteristics suitable for use with He-Ne lasers; we undertook to resolve whether a low-power (7 mW) He-Ne laser could provide sufficient excitation to permit flow cytometric detection of APC-labeled antibodies on cell surfaces. We made an APC conjugate of monoclonal antibody 4F2, which reacts with an antigen abundant on the surfaces of activated human T-lymphocytes; APC-4F2 was used to stain blood mononuclear cells that had been cultured with and without phytohemagglutinin (PHA). Cells so stained were examined in a flow cytometer with orthogonal illumination at 633 nm from a 7 mW He-Ne laser; antibody-bearing cells were detectable by fluorescence emission above 665 nm. Cells from the same cultures were stained with fluorescein-labeled 4F2 antibody and examined in a flow cytometer with argon ion laser excitation at 488 nm. Percentages of antibody-bearing cells determined from APC fluorescence and from fluorescein fluorescence were in good agreement. It thus appears that He-Ne lasers and APC-antibodies are usable for immunofluorescence measurements; the sensitivity attainable with this technique remains to be determined.

Osmolality of substances used in the intensive care nursery

It has been well documented that the administration of hypertonic substances to the newborn may result in a variety of adverse effects, including hepatic, intestinal, and/or neuronal injury. Furthermore, neonates are exposed to a large number of drugs and other substances while in the intensive care nursery setting. As few data are available that document the actual osmolality of many of the substances employed in caring for the sick neonate, the present study measured the osmolality of 64 medications as well as 23 formulas or nutritional supplements used in the intensive care nursery. Osmolality was determined by both vapor pressure and freezing point depression. Results indicate that a large number of medications normally administered by the enteral route possess a markedly elevated osmolality in excess of 2,000 mosm/kg H2O. Although parenterally administered medications normally have a much lower osmolality, several possess significantly elevated levels. It is recommended that measures be taken to minimize the osmolality of substances administered to the critically ill newborn whenever possible.

Comparison of two measures of burnout

The purposes of the study were to determine the correlations between scores on the Maslach Burnout Inventory and the Tedium Measure and to correlate these measures with job satisfaction and health problems. These relationships might suggest which one of these two leading measures of burnout has the greatest utility in future research. 78 direct service workers in mental health and mental retardation settings participated. Tedium correlated significantly with the six burnout subscales. It also correlated significantly with job satisfaction and health problems. Only the emotional exhaustion intensity sub-scale of the Maslach inventory correlated significantly with job satisfaction and health problems. The Tedium Measure is an economical instrument for measuring burnout and has significant correlations with criterion variables. The Maslach scales may be more useful in investigating patterns as well as stages of burnout and in situations involving interactions with moderator variables.

Mammary ductal elongation: differentiation of myoepithelium and basal lamina during branching morphogenesis

Elongation of mammary ducts in the immature mouse takes place as a result of rapid growth in end buds. These structures proliferate at the apex of elongating ducts and are responsible for penetration of the surrounding adipose stroma; by turning and branching, end buds give rise to the characteristic open pattern of the mammary ductal tree. We have used a variety of techniques to determine the cellular and structural basis for certain of these end bud activities, and now report the following. (1) The end bud tip is covered with a monolayer of epithelium, the "cap cells," which are characterized by a relative lack of intercellular junctions and other specialized features. (2) The cap cell layer extends along the end bud flank and neck regions where it is continuous with the myoepithelium which surrounds the subtending mature duct. A linear sequence of differentiative changes occur in the cap cells in this region as they progressively alter in shape and accumulate the cytological features of mature myoepithelium. Cap cells may therefore be defined as a stem cell population providing new myoepithelial cells for ductal morphogenesis and elongation. (3) Differentiation of cap cells into myoepithelium is associated with conspicuous changes in the basal lamina. At the tip, cap cells form a 104-nm lamina similar to that described in expanding mammary alveoli and in embryonic tissues. Along the end bud flanks the basal lamina is raised from the cell surface and extensively folded, resulting in a greatly thickened lamina, measuring as much as 1.4 microns. At the surface of the subtending ducts the lamina becomes structurally simplified and resembles that at the tip, but has a significantly greater thickness, averaging 130 nm. (4) The codifferentiation of myoepithelium and its basement membrane is associated with changes in the surrounding stroma. Undifferentiated mesenchymal-like cells attach to the surface of the basal lamina in the midportion of the end buds and become increasingly numerous in the neck region, forming a monolayer over the myoepithelial basal lamina. These stromal cells progressively differentiated into fibrocytes which participate in collagen fibrillogenesis and give rise to the fibrous components of the stroma surrounding the mature duct.

Attributional style and life-events

The study addressed the question of the significance of intervening life-events in linking attributional style and depression. Twenty male subjects who had experienced an uncontrollable event, job redundancy, were compared with 20 controls on measures of attributional style, depression and self-esteem. The reformulated helplessness hypothesis implies that attribution and depression should be correlated only after the uncontrollable event. This was found to be the case for internal--external dimension, providing tentative support for the reformulated helplessness model.

Argonne Intense Pulsed Neutron Source Used to Solve the Molecular Structure of a Novel Organometallic Complex

The single-crystal structure of Mn(CO)(3)(C(7)H(11)) is the first to be solved by direct methods based on time-of-flight neutron diffraction data obtained at the Argonne Intense Pulsed Neutron Source. The molecule contains an unusual three-center, two-electron manganese-hydrogen-carbon interaction.

Simultaneous flow cytometric analysis of human T cell activation antigen expression and DNA content

Cell-surface antigens that are induced to appear on T cells activated by the lectin phytohemagglutinin-P (PHA) can be classified both on the basis of the kinetics of their appearance and on their growth-association properties. Seven distinct T cell activation antigens, defined by monoclonal antibodies, were classified as early, intermediate, or late antigens based on their temporal appearance relative to DNA synthesis. Four antigens, the transferrin receptor, the T cell activation antigen Tac, the 4F2 antigen, and the 49.9 antigen were early antigens, whereas the OKT10 antigen appeared at intermediate times and both HLA-DR and antigen 19.2 appeared late. The use of a dye, Hoechst 33342, which stains DNA stoichiometrically, allowed the simultaneous analysis of immunofluorescence and cell cycle position of individual cells. This analysis unexpectedly revealed that essentially all cells in the proliferative phase of the cell cycle expressed each of the four early-activation antigens. The correlation between expression of the four early-activation antigens and T cell proliferation suggests that these molecules are important for the growth of all T cells. The relationship of two of these activation antigens, known to be the receptors for transferrin and interleukin 2, a T cell growth factor, is discussed with special reference to the roles of their ligands in supporting the growth of T cells.

Luminance-dependent visual latency for the Hess effect, the Pulfrich effect, and simple reaction time

The Hess effect, a monocular, latency-based illusion in which the more intensely illuminated of a pair of laterally-moving targets appears displaced ahead of the other, was studied with white targets on black background at scotopic and photopic levels. The magnitude of the Hess effect was about the same as that of the Pulfrich effect under similar photopic conditions. Reaction time declined more rapidly with increasing stimulus intensity than would have been predicted either by the Hess or the Pulfrich effect. Theoretical time-constants, computed for the Hess effect by assuming a first-order diffusion process followed by a more central non-linearity (temporal centroid), ranged between 0.145 and 0.165 sec for three observers.

Piperacillin and gentamicin v carbenicillin and gentamicin for treatment of serious gram-negative infections

Piperacillin sodium, a new penicillin with remarkable in vitro activity against Pseudomonas aeruginosa and other Gram-negative bacilli, and gentamicin sulfate were compared with carbenicillin disodium and gentamicin in a prospective, randomized, double-blind comparison for treating serious Gram-negative infections. Of the 32 patients whose courses were "evaluable" for efficacy, 12 of 14 who received piperacillin and gentamicin and 13 of 18 who received carbenicillin and gentamicin had favorable outcomes. Of the 99 patients whose courses were evaluable for toxicity, nine of 51 recipients of piperacillin and gentamicin and 15 of 48 recipients of carbenicillin and gentamicin suffered clinical reactions possibly, probably, or definitely related to the penicillin. No statistically significant differences were found in the two groups in the frequencies of biochemical abnormalities, including hypokalemia, that occurred in 19 or 44 recipients of piperacillin and gentamicin and 16 of 45 recipients of carbenicillin and gentamicin. Thus, this study did not prove differences in efficacy of toxicity for piperacillin and gentamicin plus carbenicillin and gentamicin for serious Gram-negative infections.

Encircling endocardial ventriculotomy for refractory ischemic ventricular tachycardia. III. Effects on regional left ventricular function

In order to assess the effects of the encircling endocardial ventriculotomy (EEV) on regional left ventricular function, we cannulated seven adult mongrel dogs for cardiopulmonary bypass. Two pairs of miniature pulse-transit transducers were placed in mid-myocardium of the left ventricle, one pair in a region that would later be encompassed by an EEV and the other pair in a region of remote normal myocardium. Pressure-dimension data were analyzed during vena caval occlusions (after volume loading) both on and off cardiopulmonary bypass and both before and after performance of an EEV. The EEV results in a significant decrease in diastolic compliance of the encompassed myocardium. No significant compliance changes occurred in the control regions of the same hearts. This change in regional diastolic compliance is partially responsible for a loss of systolic excursion within the EEV-encompassed region and may help to explain the severe left ventricular dysfunction that has been observed in some patients following an EEV.

Encircling endocardial ventriculotomy for refractory ischemic ventricular tachycardia. II. Effects on regional myocardial blood flow

Previous experimental studies of the encircling endocardial ventriculotomy (EEV) have shown a significant alteration of normal local electrical activity within the encompassed region. Although this procedure may result in isolation of ventricular arrhythmias, the data are more suggestive of a less specific effect on regional myocardial blood flow. This study examines the effect of EEV on local myocardial blood flow using the radioactive tracer microsphere technique in 10 dogs. Flows were determined before and after an EEV with the animals on cardiopulmonary bypass at controlled perfusion pressures, temperatures, and heart rates. Blood flow was studied at subepicardial and subendocardial levels inside, outside, and bordering the EEV. Prior to performance of the EEV, subepicardial blood flow in the left ventricular myocardium ranged from 0.81 +/- 0.07 to 0.89 +/- 0.08 ml/gm/min. Subendocardial flows ranged from 0.80 +/- 0.07 to 0.91 +/- 0.09 ml/gm/min. There was no significant difference between any of the flows across each respective layer of myocardium. Following the EEV procedure, blood flow to the subendocardium within the EEV fell to 0.33 +/- 0.07 ml/gm/min, while flow to the subendocardium of the normal regions of the same hearts actually increased to 1.21 +/- 0.23 ml/gm/min. Similar changes occurred at subepicardial levels, with flow at the center of the EEV falling to 0.66 +/- 0.10 ml/gm/min despite a tendency for normal subepicardial flow to increase to 1.78 +/- 0.24 ml/gm/min. Superimposed ischemia to the EEV-encompassed myocardium, created by occlusion of the distal left anterior descending coronary artery (LAD), accentuated this abnormality by demonstrating that the region continues to receive some flow from epicardially based coronary vessels. The data from this study show that the EEV decreased regional blood flow to the encompassed myocardium and suggests that myocardial ischemia may be responsible for ablation of the delicate re-entrant mechanisms that sustain ventricular tachyarrhythmias.

Encircling endocardial ventriculotomy for refractory ischemic ventricular tachycardia. I. Electrophysiological effects

The direct endocardial surgical techniques introduced for the treatment of refractory ischemic ventricular tachyarrhythmias have resulted in decreased surgical mortality rates and increased success rates in comparison to previous indirect techniques. Since the mechanism of action of one of these new techniques, the encircling endocardial ventriculotomy (EEV), is unknown, the present study was designed to clarify the electrophysiological effects of this procedure. Epicardial and intramural electrophysiology was studied in 18 dogs before and after undergoing an EEV. In the absence of induced myocardial ischemia, the procedure caused an epicardial conduction delay of 23 +/- 3 msec (p less than 0.0001) across the boundaries of the incision. When the EEV enriched acutely ischemic myocardium, it was capable in certain instances of isolating spontaneous ventricular electrical activity to the myocardium encompassed by the incision and thereby protecting the remainder of the heart from the arrhythmia. The EEV resulted in total ablation of all (2 Mv/msec) electrical activity at 20 of 48 (42%) subendocardial electrode sites and at 12 of 44 (27%) subepicardial sites monitored within the encompassed myocardium. These data suggest that although the EEV may be capable of isolating ischemic ventricular tachyarrhythmias to the encompassed myocardium, it most commonly ablates the anatomic-electrophysiological substrate necessary for the genesis and perpetuation of these arrhythmias.

Preventive training in management of stress for reduction of physiological symptoms through increased cognitive and behavioral controls

This study tested the effectiveness of training in management of stress which combined relaxation and cognitive modification. Students in rehabilitation counseling were taught to identify individual situation-specific sources of stress to develop individual plans for the management of their particular stress. Techniques included progressive relaxation, stretching exercises, and cognitive restructuring. Sixteen participants self-selected for interest in management of stress had 12 biweekly training sessions and were compared to 16 in a no-treatment control on presence of physiological and behavioral stress symptoms and irrational beliefs. Analysis showed 16 trained participants evidenced significant reduction of stress and irrational beliefs from pre- to posttest and at 6-mo. follow-up relative to the control group. Such training as preventive education is discussed.

Evolutionary significance of the renal excretion of transferrin half-molecule fragments

It is generally thought that the duplicated structure of serum transferrin in vertebrates arose by gene duplication and fusion from a small ancestral protein. We have found that the isolated domains of transferrin are rapidly lost from the bloodstream via the kidneys. Therefore we suggest that the ancestral transferrin was not a serum protein or, alternatively, that it was not as small as the half-molecule.